Anker Power Bank, 10,000mAh Portable Charger, PowerIQ USB-C Battery Pack

Why it's worth it

A 10,000mAh battery that's slim enough to leave in a door pocket and forget about. It'll refill an iPhone about twice, charges over USB-C in both directions, and it's the size of a phone that got a little thick.

If your phone is your GPS, your music, and your camera, the car's own USB port often can't keep up. Navigation with the screen on drains a battery faster than most cars replenish it, especially in an older vehicle. A 10,000mAh pack closes that gap without you having to think about it. Anker rates it at roughly two full charges for an iPhone 15 and just under two for a Galaxy S23.

The USB-C port works in both directions, which is the feature that makes it easy to live with. You recharge the pack with the same cable you use to charge your phone. No hunting for a micro-USB cable in a drawer. Owners who travel regularly describe the routine the same way: plug it in overnight at the hotel, drop it in the bag in the morning, don't think about it again.

From our review of 10 car travel accessories, by Paul Evans, Technical Reviewer

What we like

• +If your phone is your GPS, your music, and your camera, the car's own USB port often can't keep up
• +The USB-C port works in both directions, which is the feature that makes it easy to live with
• +It's genuinely thin — about 0.6 inches — and weighs around 8.5 ounces

What to know

• –Ten thousand milliamp-hours is a day of insurance, not a weekend of independence
• –The pack itself takes a few hours to refill, so it's an overnight item rather than a quick top-up